Debugging in Software Engineering SE Unit-4 Part-6.pdf
- 1. Debugging in Software Engineering • Debugging in Software Engineering is the process of identifying and resolving errors or bugs in a software system. • It’s a critical aspect of software development, ensuring quality, performance, and user satisfaction. Despite being time-consuming, effective debugging is essential for reliable and competitive software products. • debugging is the process of fixing a bug in the software. When there’s a problem with software, programmers analyze the code to figure out why things aren’t working correctly. • They use different debugging tools to carefully go through the code, step by step, find the issue, and make the necessary corrections.
- 2. Difference Between Debugging and Testing Aspects Testing Debugging Definition Testing is the process to find bugs and errors. Debugging is the process of correcting the bugs found during testing. Purpose The purpose of testing is to identify defects or errors in the software system The purpose of debugging is to fix those defects or errors. Focus It is the process to identify the failure of implemented code. It is the process to give absolution to code failure. Timing Testing is done before debugging Debugging is done after testing Approach Testing involves executing the software system with test cases Debugging involves analyzing the symptoms of a problem and identifying the root cause of the problem Tools and Technique Testing can involve using automated or manual testing tools Debugging typically involves using tools and techniques such as logging, tracing, and code inspection.
- 4. Process of Debugging ❑Step 1: Reproduce the Bug • To start, you need to recreate the conditions that caused the bug. This means making the error happen again so you can see it firsthand. • Seeing the bug in action helps you understand the problem better and gather important details for fixing it. ❑Step 2: Locate the Bug • Next, find where the bug is in your code. This involves looking closely at your code and checking any error messages or logs. • Developers often use debugging tools to help with this step.
- 5. ❑Step 3: Identify the Root Cause • Now, figure out why the bug happened. Examine the logic and flow of your code and see how different parts interact under the conditions that caused the bug. • This helps you understand what went wrong. ❑Step 4: Fix the Bug • Once you know the cause, fix the code. This involves making changes and then testing the program to ensure the bug is gone. • Sometimes, you might need to try several times, as initial fixes might not work or could create new issues. • Using a version control system helps track changes and undo any that don’t solve the problem.
- 6. ❑Step 5: Test the Fix • After fixing the bug, run tests to ensure everything works correctly. These tests include: • Unit Tests: Check the specific part of the code that was changed. • Integration Tests: Verify the entire module where the bug was found. • System Tests: Test the whole system to ensure overall functionality. • Regression Tests: Make sure the fix didn’t cause any new problems elsewhere in the application. ❑Step 6: Document the Process • Finally, record what you did. Write down what caused the bug, how you fixed it, and any other important details. • This documentation is helpful if similar issues occur in the future.
- 7. Debugging Approaches/Strategies 1.Brute Force: Study the system for a longer duration to understand the system. It helps the debugger to construct different representations of systems to be debugged depending on the need. A study of the system is also done actively to find recent changes made to the software. 2.Backtracking: Backward analysis of the problem which involves tracing the program backward from the location of the failure message to identify the region of faulty code. A detailed study of the region is conducted to find the cause of defects. 3.Forward analysis of the program involves tracing the program forwards using breakpoints or print statements at different points in the program and studying the results. The region where the wrong outputs are obtained is the region that needs to be focused on to find the defect. 4.Using A debugging experience with the software debug the software with similar problems in nature. The success of this approach depends on the expertise of the debugger. 5.Cause elimination: it introduces the concept of binary partitioning. Data related to the error occurrence are organized to isolate potential causes.
- 8. 6.Static analysis: Analyzing the code without executing it to identify potential bugs or errors. This approach involves analyzing code syntax, data flow, and control flow. 7.Dynamic analysis: Executing the code and analyzing its behavior at runtime to identify errors or bugs. This approach involves techniques like runtime debugging and profiling. 8.Collaborative debugging: Involves multiple developers working together to debug a system. This approach is helpful in situations where multiple modules or components are involved, and the root cause of the error is not clear. 9.Logging and Tracing: Using logging and tracing tools to identify the sequence of events leading up to the error. This approach involves collecting and analyzing logs and traces generated by the system during its execution. 10.Automated Debugging: The use of automated tools and techniques to assist in the debugging process. These tools can include static and dynamic analysis tools, as well as tools that use machine learning and artificial intelligence to identify errors and suggest fixes.
- 9. Examples of error during debugging
- 11. Debugging Tools ❑1. Integrated Development Environments (IDEs) • IDEs like Visual Studio, Eclipse, and PyCharm offer features for software development, including built-in debugging tools. These tools allow developers to: • Execute code line-by-line (step debugging) • Stop program execution at specific points (breakpoints) • Examine the state of variables and memory • IDEs support many programming languages and scripting languages, often through open-source plugins. ❑2. Standalone Debuggers • Standalone debuggers like GDB (GNU Debugger) provide advanced debugging features: • Conditional breakpoints and watchpoints • Reverse debugging (running a program backwards)
- 12. ❑3. Logging Utilities • Logging utilities log a program’s state at various points in the code, which can then be analyzed to find problems. Logging is particularly useful for debugging issues that only occur in production environments. ❑4. Static Code Analyzers • Static code analysis tools examine code without executing it to find potential errors and deviations from coding standards. They focus on the semantics of the source code, helping developers catch common mistakes and maintain consistent coding styles. ❑5. Dynamic Analysis Tools • Dynamic analysis tools monitor software as it runs to detect issues like resource leaks or concurrency problems. These tools help catch bugs that static analysis might miss, such as memory leaks or buffer overflows. ❑6. Performance Profilers • Performance profilers help developers identify performance bottlenecks in their code. They measure: • CPU usage • Memory usage • I/O operations
- 13. Advantages of Debugging 1.Improved system quality: By identifying and resolving bugs, a software system can be made more reliable and efficient, resulting in improved overall quality. 2.Reduced system downtime: By identifying and resolving bugs, a software system can be made more stable and less likely to experience downtime, which can result in improved availability for users. 3.Increased user satisfaction: By identifying and resolving bugs, a software system can be made more user-friendly and better able to meet the needs of users, which can result in increased satisfaction. 4.Reduced development costs: Identifying and resolving bugs early in the development process, can save time and resources that would otherwise be spent on fixing bugs later in the development process or after the system has been deployed. 5.Increased security: By identifying and resolving bugs that could be exploited by attackers, a software system can be made more secure, reducing the risk of security breaches.
- 14. Disadvantages of Debugging 1.Time-consuming: Debugging can be a time-consuming process, especially if the bug is difficult to find or reproduce. This can cause delays in the development process and add to the overall cost of the project. 2.Requires specialized skills: Debugging can be a complex task that requires specialized skills and knowledge. This can be a challenge for developers who are not familiar with the tools and techniques used in debugging. 3.Can be difficult to reproduce: Some bugs may be difficult to reproduce, which can make it challenging to identify and resolve them. 4.Can be difficult to diagnose: Some bugs may be caused by interactions between different components of a software system, which can make it challenging to identify the root cause of the problem. 5.Can be difficult to fix: Some bugs may be caused by fundamental design flaws or architecture issues, which can be difficult or impossible to fix without significant changes to the software system.